[Patch V2 1/4] xen: build infrastructure for generating hypercall depending symbols

[Juergen Gross <jgross@suse.com>]

Today there are several places in the kernel which build tables
containing one entry for each possible Xen hypercall. Create an
infrastructure to be able to generate these tables at build time.

Based-on-patch-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/syscalls/Makefile |  9 +++++++++
 scripts/xen-hypercalls.sh  | 12 ++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 scripts/xen-hypercalls.sh

diff --git a/arch/x86/syscalls/Makefile b/arch/x86/syscalls/Makefile
index 3323c27..a55abb9 100644
--- a/arch/x86/syscalls/Makefile
+++ b/arch/x86/syscalls/Makefile
@@ -19,6 +19,9 @@ quiet_cmd_syshdr = SYSHDR  $@
 quiet_cmd_systbl = SYSTBL  $@
       cmd_systbl = $(CONFIG_SHELL) '$(systbl)' $< $@
 
+quiet_cmd_hypercalls = HYPERCALLS $@
+      cmd_hypercalls = $(CONFIG_SHELL) '$<' $@ $(filter-out $<,$^)
+
 syshdr_abi_unistd_32 := i386
 $(uapi)/unistd_32.h: $(syscall32) $(syshdr)
 	$(call if_changed,syshdr)
@@ -47,10 +50,16 @@ $(out)/syscalls_32.h: $(syscall32) $(systbl)
 $(out)/syscalls_64.h: $(syscall64) $(systbl)
 	$(call if_changed,systbl)
 
+$(out)/xen-hypercalls.h: $(srctree)/scripts/xen-hypercalls.sh
+	$(call if_changed,hypercalls)
+
+$(out)/xen-hypercalls.h: $(srctree)/include/xen/interface/xen*.h
+
 uapisyshdr-y			+= unistd_32.h unistd_64.h unistd_x32.h
 syshdr-y			+= syscalls_32.h
 syshdr-$(CONFIG_X86_64)		+= unistd_32_ia32.h unistd_64_x32.h
 syshdr-$(CONFIG_X86_64)		+= syscalls_64.h
+syshdr-$(CONFIG_XEN)		+= xen-hypercalls.h
 
 targets	+= $(uapisyshdr-y) $(syshdr-y)
 
diff --git a/scripts/xen-hypercalls.sh b/scripts/xen-hypercalls.sh
new file mode 100644
index 0000000..676d922
--- /dev/null
+++ b/scripts/xen-hypercalls.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+out="$1"
+shift
+in="$@"
+
+for i in $in; do
+	eval $CPP $LINUXINCLUDE -dD -imacros "$i" -x c /dev/null
+done | \
+awk '$1 == "#define" && $2 ~ /__HYPERVISOR_[a-z][a-z_0-9]*/ { v[$3] = $2 }
+	END {   print "/* auto-generated by scripts/xen-hypercall.sh */"
+		for (i in v) if (!(v[i] in v))
+			print "HYPERCALL("substr(v[i], 14)")"}' | sort -u >$out
-- 
2.1.2